Throughout the day, users experienced various problems with the picture-messaging service: Many couldn't send or receive MMS text messages at all. Some reported that it was taking up to 20 minutes to send each message. Other frustrated users got halfway through dispatching a text, only to be greeted with an error message.

"Up and running in Atlanta," one of our readers wrote early on Friday afternoon. "But when [the MMS service] updated it bricked my phone for a bit. Had to do a hard reset just to start it back running. VERY slow. Sometimes fails to send but guess it is from all the traffic." Others were more succinct: "Updates phone. Tried to send a message. Failed," reported a reader in Las Vegas.

To judge by the volume of complaints on the official AT&T Facebook page, many users are still having problems sending picture messages. But in an email this morning to Computerworld, AT&T spokesman Mark Siegelsaid the company was "pleased" with the way the MMS service had been implemented on the iPhone.

Well, OK. But you tell us: Have you downloaded the update? Talk to us in the comments section, or on Twitter, @csmhorizonsblog.